1. Field of the Invention
The present invention relates to pressure regulator, and more particularly, to those regulators using internal pressure balances for proper operation.
2. Prior Art
Pressure regulators to date which have relied on the internal balancing of fluid forces for operation, have been noted for their structural complexity and cost. Frequently, numerous springs, diaphragms and machined pieces were necessary to obtain a functional assembly. In addition, although the concept of balancing internal forces within a valve to ease operation is known in the Art, prior to the present invention, no regulator valve of which the applicant is aware balanced inlet pressure while using the outlet pressure to directly open or close the valve in response to a predetermined biasing force.
An example of a pressure balanced regulator is U.S. Pat. No. 3,756,558 by Okui. Okui discloses a fluid control valve having an inlet 17 and an outlet 21, with a moving member between the inlet and outlet chambers. In the Okui valve, both the input and output portions of his device are pressure balanced, thereby requiring additional structure to sense the outlet pressure and control the moving member for regulation of flow. This additional structure adds cost to the device, and increases the likelihood of breakdown. As will be discussed below, the present invention minimizes cost and subsequent breakdowns by providing a simple but effective use of internal pressure balancing.
An additional example of previous pressure regulating valves is U.S. Pat. No. 702,266 by Webb. As with Okui, Webb discloses a valve which is pressure balanced on the input side. However, there is no pressure balance on the output side of Webb's device and thus the total outlet pressure acts to close the valve. Thus, Webb does not permit control of the valve actuation forces through the use of the natural output pressure passing through the valve.
Accordingly, there exists a need for a pressure regulating valve which is structurally simpler and more cost effective than existing valves.